Two small arms, mounted on Curiosity's mast (seen in this image just above the technician's hands), will act as a miniature weather station, monitoring wind speed, wind direction, and air temperature, according to NASA.
In this image, a technician installs the Rover Environmental Monitoring Station (REMS) in September 2010 inside a clean room at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
Other sensors in the REMS, which is provided by Spain's Ministry of Science and Innovation and its Center for Industrial Technology Development, will monitor humidity and ground temperature, NASA says.
REMS also includes an ultraviolet-light sensor on the rover deck and an air-pressure sensor mounted inside the rover's body along with the instrument's data recorder and electronic controls.
A high-gain antenna on-board Curiosity allows direct communications between the rover and Earth, using X-band radio transmissions.